PSYC23 - Lecture 10 - Mar22.docx

23 views4 pages
19 Apr 2012
LBalaquiao Page 1
March 22nd, 2012
Polyvagal Theory
- 2 distinct branches of the vagus nerve --> different evolutionary stress responses in mammals
o Older system --> primitive --> fight/flight behaviour (immobilization)
o New system --> more evolved --> linked to inhibition of behaviours, communication and
- Opposes the SAM stress response --> Sympathetic-adrenal system
- Vagal tone physiological indicator of stress
Evolutionary Perspective
- Structures
o Dorsal motor nucleus (DMNX) --> older system --> vegetative vagus
Activated when the more evolved branch fails
o Ventrolateral motor nucleus (NA) --> newer system (more evolved) --> smart vagus
o Mylinated vs. Unmylinated --> Some vagal fibers are mylinated and some aren’t -->
Mylinated = more efficient = activated by the newer system (likes to operate
with the smarter one)
- Organization
o Hierarchical --> over the course of evolution we’ve been adding newer and newer
systems --> cumulative effect, integrated into the older system
Newer vagus takes precedence over the older vagus in mammals --> older
system is used when the newer system fails
o Phylogeny recapitulates ontogeny --> you will see things in an egg that look like a more
primitive species --> a lot of similarity in the structures that are developing; all the
different species develop through a lot of the same structures which are repeated
Seeing a new species develop, you can see shapes of the older structures that
are from ancient species; from much earlier primitive species
o Dissolution
Stress and Disease
the first system that fails is always the newer system --> ventrolateral
will go first before the older system
Coping --> each of these functions are associated with a specific function
associated with how we cope in the world
Evolutionary Perspectives: strategies
- Social communication (newer system)
o Facial expression
o Attention (head turning)
o Vocalization
o Listening
- Mobilization (sympathetic nervous system) --> Feeds back to sympathetic adrenal medulla
Unlock document

This preview shows page 1 of the document.
Unlock all 4 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.